Pathogenesis of Nerve Injury: Role of Tissue Inhibitor of Metalloproteinases-1 (TIMP-1)

在战伤中，大部分战伤是由外伤引起的周围神经系统（PNS）损伤。 尽管PNS的再生能力很高，但患者会出现严重的神经性疼痛，不适合治疗。 镇痛治疗2017年国会阿片类药物和STOP倡议法案呼吁“扩大，加强， 协调基础、转化和临床研究” 并开发新的非成瘾性疼痛 治疗。 除了身体和情感上的残疾，慢性疼痛在美国的花费超过美元。 每年六千亿 年超过65%的美国退伍军人报告疼痛，其中退伍军人的严重疼痛比非退伍军人高40%。 老兵 我们的无偏转录组学研究在24小时内发现了金属蛋白酶组织抑制剂-1（TIMP-1）。 疼痛性PNS损伤中的前10个诱导基因（在数千个受调节的基因中）。TIMP-1的主要功能是 抑制细胞外蛋白酶的基质金属蛋白酶（MMP）家族。在这一框架内， Merit项目，我们开创了MMP/TIMP轴在PNS损伤和疼痛调节中的研究。这 更新申请集中在我们的第二个无偏发现：TIMP-1是X染色体连锁基因， 在疼痛性PNS损伤中表现出多态性、异常性和性别依赖性转录异构体。 我们的数据有力地表明，TIMP-1是一种镇痛，促生存和再生因子诱导的PNS 以应对伤害。然而，多态性的异常TIMP-1转录变体的表达，可能 导致功能失调的基因或蛋白质产物，易患慢性疼痛。与我们 MMP/TIMP和PNS研究的创新工具和概念、突破性数据和良好记录， 我们的目标是研究细胞和亚细胞，包括TIMP-1分布的核模式，相互作用， 在PNS损伤中的作用（目的1）。然后，我们将确定TIMP-1基因的性别特异性，异常，转录变体 由于性二态性（女性X染色体失活）和单态性（两者都普遍存在）而产生 性别）表观遗传异常（目的2）。由于多态性TIMP-1变异体发生在人类中，我们预计我们的 这些发现将迅速转化为临床环境中疼痛状态的医学表观遗传诊断。最后我们 目的：研究TIMP-1基因在PNS损伤和疼痛中的靶向治疗作用（目的3）。 该计划采用多学科最先进的技术（例如RNA-seq，SMRT-BS，BioID，Chip） 以及研究PNS损伤和疼痛的基本神经病理学和行为学方法。我们预计 我们的项目将对疼痛诊断和非成瘾性镇痛药的开发产生重大影响。

Extremity trauma causing peripheral nervous system (PNS) injury accounts for the majority of combat wounds. Despite high regenerative capacity of the PNS, patients develop severe neuropathic pain, not amenable to analgesic therapies. The congressional Opioids and STOP Initiative Act of 2017 calls to “expand, intensify, and coordinate fundamental, translational, and clinical research” on pain and develop new non-addictive pain treatments. In addition to physical and emotional disability, chronic pain costs the U.S. over $ 600 billion every year. Over 65% of American Veterans report pain, with severe pain 40% greater in Veterans than non- Veterans. Our unbiased transcriptomics study identified Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) among the top-10 induced (out of thousands regulated) genes in painful PNS injury. The main function of TIMP-1 is inhibition of the matrix metalloproteinase (MMP) family of extracellular proteases. In the framework of this VA Merit program, we have pioneered the study of the MMP/TIMP axis in PNS injury and pain regulation. This renewal application centers on our second unbiased finding: TIMP-1 is an X-chromosome-linked gene, exhibiting polymorphic, aberrant and sex-dependent transcript isoforms in painful PNS injury. Our data strongly suggest that TIMP-1 is an analgesic, pro-survival and regenerative factor induced in the PNS in response to injury. However, expression of polymorphic, aberrant TIMP-1 transcript variants, potentially resulting in dysfunctional gene or protein products, predisposes to chronic pain development. With our innovative tools and concepts, groundbreaking data and strong track record in MMP/TIMP and PNS research, we aim to study cellular and subcellular, including nuclear patterns of TIMP-1 distribution, interactors and functions in PNS injury (Aim 1). We will then identify sex-specific, aberrant, transcript variants of TIMP-1 gene arising due to sexually dimorphic (X chromosome inactivation in females) and monomorphic (universal in both sexes) epigenetic abnormalities (Aim 2). As polymorphic TIMP-1 variants occur in humans, we expect our findings will swiftly translate into medical epigenetic diagnostics of pain states in a clinical setting. Finally we aim to develop targeted TIMP-1 gene therapy in PNS injury and pain (Aim 3). This program employs multidisciplinary state-of-the-art (e.g. RNA-seq, SMRT-BS, BioID, ChiP) technologies and fundamental neuropathological and behavioral approaches to study PNS injury and pain. We anticipate our program will make a major impact on pain diagnostics and development of non-addictive analgesics.